The invention relates to a method of driving a display device comprising an electro-optical display medium between two supporting plates, a system of pixels arranged in rows and columns, with each pixel being at least formed by picture electrodes arranged on the facing surfaces of the supporting plates, at least one picture electrode being connected to a row or column electrode via a non-linear switching element, a row of pixels being selected by means of the switching elements via the row electrodes during at least a part of a line period, while data signals are presented via the column electrodes.
In this respect it is to be noted that the terms row electrode and column electrode in this application may be interchanged if desired, so that a column electrode may be meant where reference is made to a row electrode while simultaneously changing column electrode to row electrode.
In the Netherlands Patent Application No. 8,701,420 (corresponding to U.S. Pat. No. 5,032,831) in the name of the Applicant, a method of the type described in the opening paragraph is described, which provides a wide choice of freedom in the colour filters to be used. This is possible by giving the pixels a given adjustment per row by charging or discharging the capacitances associated with these pixels after first having discharged or charged them too far (either accurately or not).
In said Application this is realised by applying, prior to selection, an auxiliary voltage across the pixels beyond or on the limit of the voltage range to be used for picture display, for example an auxiliary voltage (reference voltage) or reset voltage.
In a preferred embodiment of the device described in this Application a zener diode is arranged between a pixel and a row or column electrode.
Such a zener diode has a strong asymmetrical current-voltage behaviour (IV-curve).